(mĭl'stēn') Argentinean-born British immunologist who conducted important research into antibodies. With Georges Köhler he developed a method of fusing together different cells to maintain antibody production. For the discovery of this technique, which is widely used in the development of drugs and in diagnostic tests for cancer and other diseases, Milstein and Köhler shared with British immunologist Niels K. Jerne the 1984 Nobel Prize for physiology or medicine.